In the U.S. and Europe, 17 sellers were arrested and $1 million of Bitcoins was seized as well as cash and drugs. Troels Oerting, head of Europol's cyber crime center, said the investigation went on for several months and witnessed the growth of the black market.

"The scope is basically everything is for sale, everything that is stolen … You might even buy a stolen car. But in general they were selling anything you would want to send with a normal mailman, the fastest business model," Oerting said, according to the news source.

Operation Onymous was led by American spy agencies – the FBI and Homeland Security – and coordinated by Europol in Europe. Using English as a common language, investigators made arrests in France, Germany, Spain and England.

Oerting did not mention how law enforcement authorities were able to gain access to dark websites given the use of anonymous Tor software. The fact that the identity of certain people operating the illegal websites became known, however, sends a clear message to other perpetrators of cyber crime that authorities are on their trail.

The Tor software package
Tor was originally created by the United States Naval Research Laboratory. It is an open source project that allows people to access the Internet without giving up their location. Many journalists, political activists, and government agencies regularly use Tor to send discreet messages, according to the Tor company website.

Tor is an acronym for "the onion router" and it refers to the multiple levels of encryption that are used to hide user locations. The software sends digital information packets to various servers around the world to conceal the trail of users so that tracking becomes nearly impossible.

Among those targeted in the raid were web pages designed to resemble popular online retail giants, even down to product review systems and site layouts.

"The business model is to create web stores on these hidden services and then use the normal transport to deliver it," Oerting said, according to The New York Times.

The dark sites sell drugs
Authorities arrested a 26-year-old man in San Francisco on Wednesday and charged him with operating Silk Road 2.0. The online marketplace was created to fill the void left by the government's closing of the original site. In recent months, Silk Road 2.0 had approximately 150,000 monthly active users and earned $8 million in monthly sales, the authorities said, according to The New York Times. The man that was arrested will face charges that include conspiracies of narcotics trafficking, money laundering and computer hacking.

As of Oct. 29, Silk Road 2.0 was filled with offerings for illegal narcotics – more than 14,000 listings for drugs.

"If you need 10 grams of cocaine they will deliver it with a courier or a mailman. You can pay for it with Bitcoin, or a credit card," Oerting said, according to the news source.

Now the website and others similar to it open to a page with the words, "This hidden site has been seized." Next to the message are logos of government agencies such as the FBI and Europol.